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Author Wang, B.; Luo, Y.; Liu, J.-hui; Li, X.; Zheng, Z.-hong; Chen, Q.-qian; Li, L.-yao; Wu, H.; Fan, Q.-ren url  openurl
  Title (up) Ion migration in in-situ leaching (ISL) of uranium: Field trial and reactive transport modelling Type Journal Article
  Year 2022 Publication Journal of Hydrology Abbreviated Journal  
  Volume 615 Issue Pages 128634  
  Keywords Acid in situ leaching, Banyan-Uul uranium deposit, Influence area, Reactive transport, Sensitivity analysis  
  Abstract Acid in-situ leaching (ISL) can be used as a mining technique for in situ uranium recover from underground. Acids and oxidants as lixiviants were continuously injected into a sandstone-type uranium deposit in Bayan-Uul (China). It was conducted to facilitate the dissolution of uranium minerals to generate uranyl ions, which could then be extracted for the recovery of uranium resources by the pumping cycle. A reactive transport model based on PHAST was developed to investigate the dynamic reactive migration process of uranium. The simulated results well reproduce the fluid dynamic evolution in the injecting and pumping units, as well as the dynamic release of uranium. The simulated leaching area indicates that the uranium ore leaching area was much larger than the acidification area. In addition, the pollution plume of uranium and acid water was larger than that of the leaching area, which can be used as a reference for uranium mining schemes. Furthermore, the parameter sensitivity analysis indicates the volume fraction of uranium ore and the reaction rate were the main factors affecting uranium leaching efficiency. Without considering the blockage of pores by precipitation, the Fe2+ in the reinjection fluid had a significant negative influence on uranium leaching.  
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  ISSN 0022-1694 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ wang_ion_2022 Serial 195  
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Author Kamash, Z. url  openurl
  Title (up) Irrigation technology, society and environment in the Roman Near East Type Journal Article
  Year 2012 Publication Journal of Arid Environments Abbreviated Journal  
  Volume 86 Issue Pages 65-74  
  Keywords Army, Urbanism, Qanats, Dams, Field systems, Irrigation channels  
  Abstract This paper uses a multi-faceted approach to understand the use and distribution of different irrigation technologies in the Roman Near East (63 BC – AD 636), looking at the ways in which social and environmental factors affected the implementation of those irrigation technologies. It is argued that no single factor can fully explain how irrigation technologies were used across time and space in this region. Instead, choices in irrigation technology seem to have been governed by a complex nexus of both social and environmental factors.  
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  ISSN 0140-1963 ISBN Medium  
  Area Expedition Conference  
  Notes Ancient Agriculture in the Middle East Approved no  
  Call Number THL @ christoph.kuells @ Kamash201265 Serial 259  
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Author Christofi, C.; Bruggeman, A.; Külls, C.; Constantinou, C. url  openurl
  Title (up) Isotope hydrology and hydrogeochemical modeling of Troodos Fractured Aquifer, Cyprus: The development of hydrogeological descriptions of observed water types Type Journal Article
  Year 2020 Publication Applied Geochemistry Abbreviated Journal  
  Volume 123 Issue Pages 104780  
  Keywords Isotope hydrology, Hydrogeochemical modelling, Hydrochemistry, Kargiotis, Troodos  
  Abstract The origin of groundwater recharge and subsequent flow paths are often difficult to establish in fractured, multi-lithological, and highly compartmentalized aquifers such as the Troodos Fractured Aquifer (TFA). As the conjunctive use of stable isotopes and hydrogeochemical data provides additional information, we established a monitoring network for stable isotopes in precipitation in Cyprus. The local meteoric water line, altitude effect and seasonal variation of stable isotopes in precipitation are derived from monitoring data. Stable isotopes and hydrogeochemical data are combined to model water-rock interactions and groundwater evolution along a complete ophiolite sequence. As a result a generic hydrogeologic description for the observed water types is developed. Isotope hydrology was applied in conjunction with hydrogeochemical modelling in Kargiotis Watershed, a major north-south transect of the TFA. PHREEQC was used for hydrogeochemical modelling to establish generic descriptions for observed water types. Mean precipitation-weighted values from 16 monitoring stations were used to calculate the Local Meteoric Water Line (LMWL), which was found to be equal to δ2H = (6.58 ± 0.13)*δ18O + (12.64 ± 0.91). A general decrease of 1.22‰ for δ2H and 0.20‰ for δ18O in precipitation was calculated per 100 m altitude. A generic groundwater evolution path was established: 1. Na/MgClHCO3, 2. MgHCO3, 3. Ca/MgHCO3, 4. Ca/MgNaHCO3, 4a. MgNa/CaHCO3/Cl, 5. NaMg/CaHCO3/Cl, 6. NaHCO3, 7. Na/MgHCO3SO4, 8. NaSO4Cl/HCO3. Hydrogeologic descriptions, consisting of groundwater origin, flow path and possible active water-rock processes, have been realised for the observed water types. The first two water types occur in serpentine and ultramafic-gabbro springs. Type 3 waters represent early stages of recharge and/or short flow paths, in gabbro whereas types 4 and 5 are typical for further percolating waters in gabbro and diabase. Water types 6 and 7 occur both in diabase and in the basal group and represent the regional flow. Water type 8 is the end member of regional, upwelling groundwater in the basal group. The presented descriptions and methods have practical applications in groundwater exploration, characterization, and protection. The methodology can be applied in other complex aquifer systems.  
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  Language english Summary Language english Original Title  
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  ISSN 0883-2927 ISBN Medium  
  Area Cyprus Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Christofi2020104780 Serial 76  
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Author Rehm-Berbenni, C.; Druta A.; Åberg, G.; Neguer J.; Külls, C.; Patrizi, G.; Pacha, T.; Kienzle, P.; Bugini, R.; Fiore, M.G. openurl 
  Title (up) Isotope Technologies Applied to the Analysis of Ancient Roman Mortars Type Book Whole
  Year 2005 Publication European Commission Abbreviated Journal  
  Volume Issue Pages  
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  Abstract Results of the CRAFT Project EVK4 CT-2001-30004  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Serial 73  
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Author Bonnetti, C.; Zhou, L.; Riegler, T.; Brugger, J.; Fairclough, M. url  openurl
  Title (up) Large S isotope and trace element fractionations in pyrite of uranium roll front systems result from internally-driven biogeochemical cycle Type Journal Article
  Year 2020 Publication Geochimica et Cosmochimica Acta Abbreviated Journal  
  Volume 282 Issue Pages 113-132  
  Keywords Activity cycle, Pyrite composition, Roll front uranium deposits, S isotope and trace element fractionation  
  Abstract Complex pyrite textures associated with large changes in isotopic and trace element compositions are routinely assumed to be indicative of multi-faceted processes involving multiple fluid and sulfur sources. We propose that the features of ore-stage pyrite from roll front deposits across the world, revealed in exquisite detail via high-resolution trace element mapping by LA-ICP-MS, reflect the dynamic internal evolution of the biogeochemical processes responsible for sulfate reduction, rather than externally driven changes in fluid or sulfur sources through time. Upon percolation of oxidizing fluids into the reduced host-sandstones, roll front systems become self-organized, with a systematic reset of their activity cycle after each translation stage of the redox interface down dip of the aquifer. Dominantly reducing conditions at the redox interface favor the formation of biogenic framboidal pyrite (δ34S from −30.5 to −12.5‰) by bacterial sulfate reduction and the genesis of the U mineralization. As the oxidation front advances, oxidation of reduced sulfur minerals induces an increased supply of sulfate and metals in solution to the bacterial sulfate reduction zone that has similarly advanced down the flow gradient. Hence, this stage is marked by increased rates of the bacterial sulfate reduction associated with the crystallization of variably As-Co-Ni-Mo-enriched concentric pyrite (up to 10,000′s of ppm total trace contents) with moderately negative δ34S values (from −13.7 to −7.5‰). A final stage of pyrite cement with low trace element contents and heavier δ34S signature (from −6.9 to +18.8‰) marks the end of the roll front activity cycle and the transition from an open to a predominantly closed system behavior (negligible advection of fresh sulfate). Blocky pyrite cement is formed using the remaining sulfate, which now becomes quickly heavy according to a Rayleigh isotope fractionation process. This ends the cycle by depleting the nutrient supplies for the sulfate-reducing bacteria and cementing pore spaces within the host sandstone, effectively restricting fluid infiltration. This internally-driven roll front activity cycle results in systematic, large S isotope and trace element fractionation. Ultimately, the long-time evolution of the basin and fluid sources control the metal endowment and evolution of the system; these events, however, are unlikely to be preserved by the roll front, as a direct result of its hydrodynamic nature.  
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  ISSN 0016-7037 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ bonnetti_large_2020 Serial 185  
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